A Phase II trial of Pfizer's tofacitinib has raised hopes for its potential as an effective treatment for ulcerative colitis (UC), an inflammatory-bowel disease affecting more than 750,000 people in the US alone.

The double-blind, placebo-controlled trial, funded by Pfizer and findings of which were published in the New England Journal of Medicine, looked at the efficacy of tofacitinib in 194 adults with severely active forms of the disease.

Patients were randomised for treatment with tofacitinib at a dose of 0.5 mg, 3 mg, 10 mg, or 15 mg or were given a placebo, twice daily for two months.

The results showed that 78% of patients taking the highest dose (15mg) of the drug experienced a clinical response - i.e a reduction in symptoms - at eight weeks, compared to 42% of patients in the placebo arm.

In addition, clinical remission was observed in 41% of patients given the 15mg dose and 48% of patients taking the 10mg dose, compared with 10% in the control group.

The findings led the researchers to conclude that patients with moderately to severely active UC treated with tofacitinib "were more likely to have clinical response and remission than those receiving placebo".

Pfizer is currently recruiting patients into Phase III studies of the drug, while the US Food and Drug Administration is deciding whether to approve tofacitinibfor use in rheumatoid arthritis.

Some analysts believe that annual sales of tofacitinib sales could overshoot $2 billion, according to the Wall Street Journal.